Tetrasodium iminodisuccinate(IDS)was used as an inhibitor in the separation of sphalerite and pyrite in the EX−Cu(II)(ethyl xanthate and Cu2+)system.The flotation test results demonstrated that IDS can effectively sep...Tetrasodium iminodisuccinate(IDS)was used as an inhibitor in the separation of sphalerite and pyrite in the EX−Cu(II)(ethyl xanthate and Cu2+)system.The flotation test results demonstrated that IDS can effectively separate sphalerite and pyrite under low alkaline conditions.Furthermore,high-quality zinc concentrates with a Zn grade of 58.48%and a recovery of 91.24%through mixed mineral flotation were obtained.The fundamental mechanisms were investigated through surface wettability tests,adsorption capacity tests,LEIS,FTIR,and XPS.The results confirmed that IDS prevents the adsorption of EX on the surface of pyrite,thereby reducing the response and reactivity of pyrite.The introduction of IDS causes the detachment of Cu2+from the Cu-activated pyrite surface.This process allowed IDS to chelate with the Fe sites on the surface of pyrite through the-COO-and N-centered active groups.By contrast,IDS exhibits weaker adhesion on the surface of Cu-activated sphalerite,making it easily displaced by EX through competitive adsorption.展开更多
The pressure and temperature increase resulting from the impact of different threats onto target materials is analyzed with a unified laboratory-scale setup.This allows deriving qualitative information on the occurrin...The pressure and temperature increase resulting from the impact of different threats onto target materials is analyzed with a unified laboratory-scale setup.This allows deriving qualitative information on the occurring phenomenology as well as quantitative statements about the relative effects sizes as a function of target material and threat.The considered target materials are steel,aluminum,and magnesium.As threats,kinetic energy penetrator,explosively formed projectile,and shaped charge jet are used.For the investigated combinations,the measured overpressures vary by a factor of up to 5 for a variation of the material,by a factor of up to 7 for a variation of the threat,and by a factor larger than 15for a simultaneous variation of both.The obtained results as well as the experimental approach are relevant for the basic understanding of impact effects and risks due to material reactivity.The paper combines two main aims.Firstly,to provide a summary of own prior work in a coherent journal article and,secondly,to review and discuss these earlier results with a new perspective.展开更多
Aluminum(Al)powder is widely applied in thermobaric explosives due to its high energy density and favorable reaction kinetics.However,the inert oxide layer(Al_(2)O_(3))on Al particles limits combustion reactivity and ...Aluminum(Al)powder is widely applied in thermobaric explosives due to its high energy density and favorable reaction kinetics.However,the inert oxide layer(Al_(2)O_(3))on Al particles limits combustion reactivity and energy efficiency.Fluoride-based surface modification has been developed as an effective approach to address this issue.Here,four classical fluoropolymers(F11,F14,PVDF,PTFE)are employed as coatings to prepare core-shell Al/Fluoropolymer.The combustion experimental results demonstrate that the core-shell Al/PTFE exhibits the highest flame propagation rate(52.88 mm·ms^(-1))and pressure output(109.02 k Pa)performance.Consequently,core-shell Al/PTFE is selected as a high-energy fuel to prepare RDX/Al/PTFE microspheres via the emulsion and solvent evaporation method,which can enhance the energy performance of RDX.The effects of the core-shell Al/PTFE ratio and RDX content on the combustion heat and pressure output are systematically investigated.The peak pressure reaches a maximum of 187.8 k Pa when the mass ratio of RDX,Al,and PTFE is 60:25:10.Additionally,RDX/Al/PTFE microspheres exhibit significantly higher laser-induced air shock velocities,detonation heat,and detonation pressure than those of pure RDX and RDX/Al.The mechanism underlying the enhanced reactivity and energetic performance is attributed to the ability of PTFE to etch the inert Al_(2)O_(3)shell on the surface of Al particles,thereby improving post-combustion reactions and significantly increasing the overall energy output of RDX explosives.This work offers a novel design strategy for high-energy structural thermobaric explosives for the practical applications.展开更多
An evidence-based control strategy for emission reduction of VOC sources can effectively solve the regional PM2.5and O3compound pollution in China.We estimated the anthropogenic VOC emission inventory in China in 2018...An evidence-based control strategy for emission reduction of VOC sources can effectively solve the regional PM2.5and O3compound pollution in China.We estimated the anthropogenic VOC emission inventory in China in 2018 and established a source profile database containing 129 sources based on localized detection and the latest research results.Then,the distribution of the ozone formation potential(OFP)and secondary organic aerosol formation potential(SOAFP)for emission sources was analyzed.Moreover,priority control routes for VOC emission sources were proposed for different periods.Anthropogenic VOC emissions in China reached 27,211.8 Gg in 2018,and small passenger cars,industrial protective coatings,biomass burning,heavy trucks,printing,asphalt paving,oil storage and transportation,coking,and oil refining were the main contributors.Industrial protective coatings,small passenger cars,and biomass burning all contributed significantly to OFP and SOAFP.Priority in emission reduction control should be given to industrial protective coatings,small passenger cars,heavy trucks,coking,printing,asphalt paving,chemical fibers,and basic organic chemical sources over the medium and long term in China.In addition,the priority control route for VOC emission sources should be adjusted according to the variations in VOC emission characteristics and regional differences,so as to obtain the maximum environmental benefits.展开更多
Background Vascular hyporeactivity and leakage are key pathophysiologic features that produce multi-organ damage upon sepsis.We hypothesized that pericytes,a group of pluripotent cells that maintain vascular integrity...Background Vascular hyporeactivity and leakage are key pathophysiologic features that produce multi-organ damage upon sepsis.We hypothesized that pericytes,a group of pluripotent cells that maintain vascular integrity and tension,are protective against sepsis via regulating vascular reactivity and permeability.Methods We conducted a series of in vivo experiments using wild-type(WT),platelet-derived growth factor receptor-β(PDGFR-β)-Cre+mT/mG transgenic mice and Tie2-Cre+Cx43^(flox/flox)mice to examine the relative contribution of pericytes in sepsis,either induced by cecal ligation and puncture(CLP)or lipopolysaccharide(LPS)challenge.In a separate set of experiments with Sprague-Dawley(SD)rats,pericytes were depleted using CP-673451,a selective PDGFR-βinhibitor,at a dosage of 40 mg/(kg·d)for 7 consecutive days.Cultured pericytes,vascular endothelial cells(VECs)and vascular smooth muscle cells(VSMCs)were used for mechanistic investigations.The effects of pericytes and pericyte-derived microvesicles(PCMVs)and candidate miRNAs on vascular reactivity and barrier function were also examined.Results CLP and LPS induced severe injury/loss of pericytes,vascular hyporeactivity and leakage(P<0.05).Transplantation with exogenous pericytes protected vascular reactivity and barrier function via microvessel colonization(P<0.05).Cx43 knockout in either pericytes or VECs reduced pericyte colonization in microvessels(P<0.05).Additionally,PCMVs transferred miR-145 and miR-132 to VSMCs and VECs,respectively,exerting a protective effect on vascular reactivity and barrier function after sepsis(P<0.05).miR-145 primarily improved the contractile response of VSMCs by activating the sphingosine kinase 2(Sphk2)/sphingosine-1-phosphate receptor(S1PR)1/phosphorylation of myosin light chain 20 pathway,whereas miR-132 effectively improved the barrier function of VECs by activating the Sphk2/S1PR2/zonula occludens-1 and vascular endothelial-cadherin pathways.Conclusions Pericytes are protective against sepsis through regulating vascular reactivity and barrier function.Possible mechanisms include both direct colonization of microvasculature and secretion of PCMVs.展开更多
The sessile drop method was applied to the experimental investigation of the wetting and spreading behaviors of liquid Mg drops on pure Ni substrates.For comparison,the experiments were performed in two variants:(1)us...The sessile drop method was applied to the experimental investigation of the wetting and spreading behaviors of liquid Mg drops on pure Ni substrates.For comparison,the experiments were performed in two variants:(1)using the Capillary Purification(CP)procedure,which allows the non-contact heating and squeezing of a pure oxide-free Mg drop;(2)by classical Contact Heating(CH)procedure.The high-temperature tests were performed under isothermal conditions(CP:760℃for 30 s;CH:715℃for 300 s)using Ar+5 wt%H_(2) atmosphere.During the sessile drop tests,images of the Mg/Ni couples were recorded by CCD cameras(57 fps),which were then applied to calculate the contact angles of metal/substrate couples.Scanning and transmission electron microscopy analyses,both coupled with energy-dispersive X-ray spectroscopy,were used for detailed structural characterization of the solidified couples.It was found that an oxide-free Mg drop obtained by the CP procedure showed a wetting phenomenon on the Ni substrate(an average contact angleθ<90°in<1 s),followed by fast spreading and good wetting over the Ni substrate(θ_((CP))~20°in 5 s)to form a final contact angle ofθ_(f(CP))~18°.In contrast,a different wetting behavior was observed for the CH procedure,where the unavoidable primary oxide film on the Mg surface blocked the spreading of liquid Mg showing apparently non-wetting behavior after 300 s contact at the test temperature.However,in both cases,the deep craters formed in the Ni substrates under the Mg drops and significant change in the structure of initially pure Mg drops to Mg-Ni alloys suggest a strong dissolution of Ni in liquid Mg and apparent values of the final contact angles measured for the Mg/Ni system.展开更多
A survey was conducted of the volatile organic compounds(VOCs)released from sources of solvent use,industry activities and vehicle emissions in Guiyang,a capital city of China.Samples were collected by canisters and a...A survey was conducted of the volatile organic compounds(VOCs)released from sources of solvent use,industry activities and vehicle emissions in Guiyang,a capital city of China.Samples were collected by canisters and analyzed by GC-MS-FID.The species profiles of VOCs emitted from sources were obtained.Results showed that xylenes,ethylbenzene,acetone and dichloromethane were the characteristics species for painting,2-propanol and ethyl acetate for printing,α-pinene for solid wood furniture manufacturing,and 2-butanone for biscuit baking.These characteristics species could be as tracers for the sources respectively.In most of samples from the solvent use,the benzene/toluene(B/T)ratio was less than 0.3,indicating that the ratio could be as the indicator for tracing the solvent use related sources.The results also suggested that the toluene/xylene(T/X)ratio be as the indicator to distinguish the VOCs sources of painting(<2)from the printing(>2).Aromatics contributed the most to ozone formation potential(OFP)of most painting and non-paper printing sources,and oxygen-containing VOCs(OVOCs)were major species contributing to OFP of the sources from food production and paper printing.The OFP of the VOCs emissions from vehicle in tunnels and from other manufactures were dominated by both aromatics and alkenes.Theα-pinene could explain 56.94%and 32.54%of total OFP of the VOCs sources from filing cabinet and solid wood furniture manufacturing,which was rarely been involved in previous studies of VOCs source profiles,indicating that the species of concern for VOCs sources are still insufficient at present.展开更多
The trade-off between efficiency and stability has limited the application of TiO_(2)as a catalyst due to its poor surface reactivity.Here,we present a modification of a TiO_(2)layer with highly stable Sub-5 nm Fe_(2)...The trade-off between efficiency and stability has limited the application of TiO_(2)as a catalyst due to its poor surface reactivity.Here,we present a modification of a TiO_(2)layer with highly stable Sub-5 nm Fe_(2)O_(3)nanoparticles(NP)by modulating its structure-surface reactivity relationship to attain efficiency-stability balance via a voltage-assisted oxidation approach.In situ simultaneous oxidation of the Ti substrate and Fe precursor using high-energy plasma driven by high voltage resulted in uniform distribution of Fe_(2)O_(3)NP embedded within porous TiO_(2)layer.Comprehensive surface characterizations with density functional theory demonstrated an improved electronic transition in TiO_(2)due to the presence of surface defects from reactive oxygen species and possible charge transfer from Ti to Fe;it also unexpectedly increased the active site in the TiO_(2)layer due to uncoordinated electrons in Sub-5 nm Fe_(2)O_(3)NP/TiO_(2)catalyst,thereby enhancing the adsorption of chemical functional groups on the catalyst.This unique embedded structure exhibited remarkable improvement in reducing 4-nitrophenol to 4-aminophenol,achieving approximately 99%efficiency in 20 min without stability decay after 20 consecutive cycles,outperforming previously reported TiO_(2)-based catalysts.This finding proposes a modified-electrochemical strategy enabling facile construction of TiO_(2)with nanoscale oxides extandable to other metal oxide systems.展开更多
The importance of selective synthesis of high-value-added chemicals from renewable resources is paramount but remains a crucial challenge in organic synthesis and chemical reformation.Herein,we report the selective ph...The importance of selective synthesis of high-value-added chemicals from renewable resources is paramount but remains a crucial challenge in organic synthesis and chemical reformation.Herein,we report the selective photosynthesis of C-C coupling products and carbonyl compounds from biomass-derived alcohols.The key to ensuring high end-to-end selectivity is the modulation of the reactivity of ketyl radical(*RCHOH)intermediates by employing different metal co-catalysts(Au,Pt,Pd,Ru)supported on Cd0.6Zn0.4S solid solution(CZS)photocatalysts.In particular,the C-C coupling product,hydrobenzion,and fully oxidized benzaldehyde were obtained from benzyl alcohol with high selectivity(>98%)over Au-CZS and Ru-CZS,respectively.Combined experimental and theoretical analyses demonstrated that the affinity of*RCHOH for the surface of metals governs their subsequent transformations,in which weak and strong radical adsorption on Au and Ru results in C-C coupling products and carbonyl compounds,respectively.展开更多
Following publication of the original article,the authors observed that both Fig.5 and Fig.4 depict the same image.Figure 5 was inaccurately referenced and displayed.The correct Fig.5 is copied below:The original arti...Following publication of the original article,the authors observed that both Fig.5 and Fig.4 depict the same image.Figure 5 was inaccurately referenced and displayed.The correct Fig.5 is copied below:The original article has been updated.展开更多
The aim of this study was to investigate the oxidation reactivity and behavior of exhaust particulate matter(PM)from diesel engines.PM samples from two diesel engines(1K,CY4102)with different emission levels were coll...The aim of this study was to investigate the oxidation reactivity and behavior of exhaust particulate matter(PM)from diesel engines.PM samples from two diesel engines(1K,CY4102)with different emission levels were collected by a thermophoretic system and a quartz filter.The oxidation reactivity,oxidation behaviors,and physicochemical properties of the PM samples were analyzed using thermogravimetric analysis(TGA),high-resolution transmission electron microscopy(HRTEM),Fourier-transform infrared spectrometry(FTIR),and Raman spectroscopy.The results showed that there was a great difference in the oxidation reactivity of soot particles emitted by the two different diesel engines.A qualitative analysis of the factors influencing oxidation reactivity showed that the nanostructure,degree of graphitization,and relative concentration of aliphatic C—H functional groups were the most important factors,whereas no significant correlation was found between the primary particle size and activation energy of the diesel soot.Based on the oxidation behavior analysis,the diesel soot particles exhibited both internal and surface oxidation modes during the oxidation process.Surface oxidation was dominant during the initial stage,and as oxidation progressed,the mode gradually changed to internal oxidation.Internal oxidation mode of soot particles from the 1K engine was significantly higher than that of CY4102.展开更多
The reactivity and stability of seventeen (17) imidazo [1,2-a]pyridine N-acylhydrazone derivatives were investigated using density functional theory at the B3LYP/6-31+ G (d, p) level. Analysis of the molecular electro...The reactivity and stability of seventeen (17) imidazo [1,2-a]pyridine N-acylhydrazone derivatives were investigated using density functional theory at the B3LYP/6-31+ G (d, p) level. Analysis of the molecular electrostatic potential (MEP) and determination of the dual descriptor revealed that in most cases, the nitrogen atoms of the 6-πelectron conjugation, the oxygen, and the sulfur atom are nucleophilic site. Chemical reactivity of the compounds was assessed through analysis of frontier molecular orbitals (HOMO and LUMO), energy gap (Δℰ), chemical hardness (η), and the softness (S). Consequently, the compound 9e exhibited the lowest reactivity, least electron donating, and the highest stability. This comprehensive study offers valuable insights into the chemical behavior of these derivatives, crucial for further exploration and potential applications.展开更多
Several works have been based on the study of thermal variations in biomass to derive more valuable products such as fuels capable of replacing oil in the event of a crisis or activated carbon used as an adsorbent mat...Several works have been based on the study of thermal variations in biomass to derive more valuable products such as fuels capable of replacing oil in the event of a crisis or activated carbon used as an adsorbent material, widely used in industry for the elimination of unwanted materials, both in liquid and gaseous environments. A study of thermal parameters such as: heating speed, retention time, drying temperature, carbonization temperature, particle size, was carried out with the aim of determining the characteristic factors of the carbonization of Polyethylene terephthalate (PET), sawdust (SC) and sawdust/polyethylene terephthalate (CPS) mixture. The results of the immediate analysis revealed a very low level of ash in PET (0.013%) compared to the level of ash in sawdust (2.9%), as well as a high level of fixed carbon (82.960%), which suggests the presence of mineral oxides and a significant carbon matrix unlike PET, which indicates a very significant organic matrix (essentially made up of organic matter) with the absence of mineral oxides. The study of thermal parameters showed the water loss from Sawdust (SC) and the Sawdust/Polyethylene terephthalate (CPS) mixture, an increase with temperature, unlike that of PET whose variation is essentially zero. Without heat treatment, sawdust alone contains approximately 7% water. The optimal drying temperature for this study is 110˚C for a stay of 24 hours. It appears that the largest mass losses for the PET samples are between 87.19% and 96.05%, followed by that of the mixture, between 47.33% and 64.37%. And the lowest are observed, those of sawdust (from 24.02% to 62.6%). However, here we can say that the influence of the mass is not great, given the slight difference between the losses by temperature. The results of the study of the influence of grain size showed that the differences are insignificant, even if we vary the diameter of the grains from simple to triple. To better minimize physical constraints such as the intragranular diffusibility of the volatile matter and the homogeneity of the temperature in the grains, 75 μm particles are found to be optimal for our study. It can be noted when studying the heating rate that the mass loss at the end of the reaction is approximately the same depending on each precursor material. However, it has been demonstrated that the heating rate strongly influences the nature of the reaction products both for volatile materials and for the solid residue as well as on the kinetic parameters of the chemical reaction. Furthermore, the variation in apparent density shows a decrease as a function of the increase in the residence time of the materials in the reactor. As the carbonization time increases, the apparent density decreases. We note, for the lignocellulosic material, that the apparent density stabilizes after 60 minutes.展开更多
The electronic property of pyrite supercell containing As,Se,Te,Co or Ni hetero atoms were calculated using density functional theory（DFT）,and the reactivities of pyrite with oxygen and xanthate were discussed by fr...The electronic property of pyrite supercell containing As,Se,Te,Co or Ni hetero atoms were calculated using density functional theory（DFT）,and the reactivities of pyrite with oxygen and xanthate were discussed by frontier orbital methods.The cell volume expands due to the presence of impurity.Co and Ni mainly affect the bands near Fermi levels,while As mainly affects the shallow and deep valence bands,and Se and Te mainly affect the deep valence bands.Electronic density analysis suggests that there exists a strong covalent interaction between hetero atom and its surrounding atoms.By frontier orbital calculation,it is suggested that As,Co and Ni have greater influence on the HOMO and LUMO of pyrite than Se and Te.In addition,pyrite containing As,Co or Ni is easier to oxidize by oxygen than pyrite containing Se or Te,and pyrite containing Co or Ni has greater interaction with collector.These are in agreement with the observed pyrite practice.展开更多
Effect of sulfur impurity on coke reactivity was investigated by simulating petroleum coke with low-impurity pitch coke and impurities doping. And its mechanism was discussed by X-ray diffraction (XRD), scanning elect...Effect of sulfur impurity on coke reactivity was investigated by simulating petroleum coke with low-impurity pitch coke and impurities doping. And its mechanism was discussed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The results show that sulfur has strong catalysis on both air and CO2 reactivity of coke in the case of no other impurity interference. Its catalysis is probably realized by triggering organic sulfur→H2S→SO2→COS and elemental sulfur (Sx)→SO2 and organic sulfur→H2S→COS→Sx→C2S→COS reaction systems during coke?O2 and coke?CO2 reactions, respectively, which are partly circular with functions of increasing carbon consumption and enlarging coke specific surface area.展开更多
The formations and transformations of the chemical bonds of reactants and intermediates on cata- lyst surfaces occur in conjunction with the evolution of heat during catalytic reactions. Measure- ment of this evolved ...The formations and transformations of the chemical bonds of reactants and intermediates on cata- lyst surfaces occur in conjunction with the evolution of heat during catalytic reactions. Measure- ment of this evolved heat is helpful in terms of understanding the nature of the interactions be- tween the catalyst and the adsorbed species, and provides insights into the reactivity of the catalyst. Although various techniques have previously been applied to assessments of evolved heat, direct measurements using a Tian-Calvet microcalorimeter are currently the most reliable method for this purpose. In this review, we summarize the relationship between the adsorption/reaction energetics determined by microcalorimetry and the reactivities of supported catalysts, and examine the im- portant role of microcalorimetry in understanding catalytic performance from the energetic point of view.展开更多
Various platelet function tests are currently used to identify responsiveness to antiplatelet therapy. 176 ACS patients were enrolled and Linear regression and Kappa consistency analysis showed there was a significant...Various platelet function tests are currently used to identify responsiveness to antiplatelet therapy. 176 ACS patients were enrolled and Linear regression and Kappa consistency analysis showed there was a significant but moderate correlation between platelet inhibition rate and a significant but fair agreement between high clopidogrel on-treatment platelet reactivity tested by light transmission aggregometry and thrombelastography.展开更多
Objectives:We sought to determine whether high posttreatment platelet reactivity(HPPR)to a 600 mg loading dose of clopidogrel affects outcomes in Chinese patients with acute coronary syndrome(ACS)following percutaneou...Objectives:We sought to determine whether high posttreatment platelet reactivity(HPPR)to a 600 mg loading dose of clopidogrel affects outcomes in Chinese patients with acute coronary syndrome(ACS)following percutaneous coronary intervention(PCI)and to investigate whether there is a relationship between the number of platelet reactivity units(PRUs)and the characteristics of the patients.Background:Although impaired platelet response to clopidogrel is a strong predictor of unfavorable outcome after PCI,the impact of HPPR to a 600 mg loading dose of clopidogrel in Chinese patients with ACS undergoing PCI is still unknown.Methods:We performed observational research on 134 unselected patients with ACS undergoing urgent or planned PCI with a 600 mg loading dose of clopidogrel.Platelet activation was expressed as the PRU value measured by the VerifyNow assay.Results:Among the 134 patients(mean age 60.62 years[standard deviation 9.13 years],60.4%male),there were 46 patients with HPPR(34.3%)and 88 patients without HPPR(65.7%).At a mean follow-up of 6 months(standard deviation 1 month),the rates of cardiac death,unstable angina,and rehospitalization for target lesion revascularization were higher in the HPPR group(19.6%vs.6.8%,P=0.029).Multivariate analysis identifi ed hemoglobin level and sex as independent predictors of the PRU value(y=456.355−1.736 x 1−31.880 x 2,P<0.05).On receiver operating characteristic curve analysis,PRU values could signifi cantly discriminate between patients with and patients without cardiac death,unstable angina,and rehospitalization for target lesion revascularization(area under the curve 0.758,95%confi dence interval 0.62–0.85,P=0.001,P<0.05).Conclusion:In patients with ACS,HPPR to a 600 mg loading dose of clopidogrel is associated with worse outcomes after PCI.There is some relationship between the PRU value and the hemoglobin level and sex.PRU values can predict the prognosis.展开更多
The paper describes the instrumentation for studying temperature and void reactivity effects that were developed at VR-I zero power reactor. Further are described its operational parameters, fields and ways of its uti...The paper describes the instrumentation for studying temperature and void reactivity effects that were developed at VR-I zero power reactor. Further are described its operational parameters, fields and ways of its utilization as well as issues connected to its implementation into the reactor core.展开更多
Antiplatelet therapy with aspirin or clopidogrel or both is the standard care for patients with proven coronary or peripheral arterial disease,especially those undergoing endovascular revascularization procedures. How...Antiplatelet therapy with aspirin or clopidogrel or both is the standard care for patients with proven coronary or peripheral arterial disease,especially those undergoing endovascular revascularization procedures. However,despite the administration of the antiplatelet regiments,some patients still experience recurrent cardiovascular ischemic events. So far,it is well documented by several studies that in vitro response of platelets may be extremely variable. Poor antiplatelet effect of clopidogrel or high on-treatment platelet reactivity(HTPR) is under investigation by numerous recent studies. This review article focuses on methods used for the ex vivo evaluation of HTPR,as well as on the possible underlying mechanisms and the clinical consequences of this entity. Alternative therapeutic options and future directions are also addressed.展开更多
基金supports from the National Natural Science Foundation of China(No.52174272)the Fundamental Research Funds for the Central Universities of Central South University,China(No.2021zzts0306)the Hunan Provincial Natural Science Foundation of China(No.2020JJ5736).
文摘Tetrasodium iminodisuccinate(IDS)was used as an inhibitor in the separation of sphalerite and pyrite in the EX−Cu(II)(ethyl xanthate and Cu2+)system.The flotation test results demonstrated that IDS can effectively separate sphalerite and pyrite under low alkaline conditions.Furthermore,high-quality zinc concentrates with a Zn grade of 58.48%and a recovery of 91.24%through mixed mineral flotation were obtained.The fundamental mechanisms were investigated through surface wettability tests,adsorption capacity tests,LEIS,FTIR,and XPS.The results confirmed that IDS prevents the adsorption of EX on the surface of pyrite,thereby reducing the response and reactivity of pyrite.The introduction of IDS causes the detachment of Cu2+from the Cu-activated pyrite surface.This process allowed IDS to chelate with the Fe sites on the surface of pyrite through the-COO-and N-centered active groups.By contrast,IDS exhibits weaker adhesion on the surface of Cu-activated sphalerite,making it easily displaced by EX through competitive adsorption.
文摘The pressure and temperature increase resulting from the impact of different threats onto target materials is analyzed with a unified laboratory-scale setup.This allows deriving qualitative information on the occurring phenomenology as well as quantitative statements about the relative effects sizes as a function of target material and threat.The considered target materials are steel,aluminum,and magnesium.As threats,kinetic energy penetrator,explosively formed projectile,and shaped charge jet are used.For the investigated combinations,the measured overpressures vary by a factor of up to 5 for a variation of the material,by a factor of up to 7 for a variation of the threat,and by a factor larger than 15for a simultaneous variation of both.The obtained results as well as the experimental approach are relevant for the basic understanding of impact effects and risks due to material reactivity.The paper combines two main aims.Firstly,to provide a summary of own prior work in a coherent journal article and,secondly,to review and discuss these earlier results with a new perspective.
基金supported by the National Natural Science Foundation of China(Grant Nos.T2222027 and 12202416)。
文摘Aluminum(Al)powder is widely applied in thermobaric explosives due to its high energy density and favorable reaction kinetics.However,the inert oxide layer(Al_(2)O_(3))on Al particles limits combustion reactivity and energy efficiency.Fluoride-based surface modification has been developed as an effective approach to address this issue.Here,four classical fluoropolymers(F11,F14,PVDF,PTFE)are employed as coatings to prepare core-shell Al/Fluoropolymer.The combustion experimental results demonstrate that the core-shell Al/PTFE exhibits the highest flame propagation rate(52.88 mm·ms^(-1))and pressure output(109.02 k Pa)performance.Consequently,core-shell Al/PTFE is selected as a high-energy fuel to prepare RDX/Al/PTFE microspheres via the emulsion and solvent evaporation method,which can enhance the energy performance of RDX.The effects of the core-shell Al/PTFE ratio and RDX content on the combustion heat and pressure output are systematically investigated.The peak pressure reaches a maximum of 187.8 k Pa when the mass ratio of RDX,Al,and PTFE is 60:25:10.Additionally,RDX/Al/PTFE microspheres exhibit significantly higher laser-induced air shock velocities,detonation heat,and detonation pressure than those of pure RDX and RDX/Al.The mechanism underlying the enhanced reactivity and energetic performance is attributed to the ability of PTFE to etch the inert Al_(2)O_(3)shell on the surface of Al particles,thereby improving post-combustion reactions and significantly increasing the overall energy output of RDX explosives.This work offers a novel design strategy for high-energy structural thermobaric explosives for the practical applications.
基金financially supported by the National Natural Science Foundation of China (No.51638001)National Joint Center for Air Pollution Prevention and Control (No.DQGG202010)。
文摘An evidence-based control strategy for emission reduction of VOC sources can effectively solve the regional PM2.5and O3compound pollution in China.We estimated the anthropogenic VOC emission inventory in China in 2018 and established a source profile database containing 129 sources based on localized detection and the latest research results.Then,the distribution of the ozone formation potential(OFP)and secondary organic aerosol formation potential(SOAFP)for emission sources was analyzed.Moreover,priority control routes for VOC emission sources were proposed for different periods.Anthropogenic VOC emissions in China reached 27,211.8 Gg in 2018,and small passenger cars,industrial protective coatings,biomass burning,heavy trucks,printing,asphalt paving,oil storage and transportation,coking,and oil refining were the main contributors.Industrial protective coatings,small passenger cars,and biomass burning all contributed significantly to OFP and SOAFP.Priority in emission reduction control should be given to industrial protective coatings,small passenger cars,heavy trucks,coking,printing,asphalt paving,chemical fibers,and basic organic chemical sources over the medium and long term in China.In addition,the priority control route for VOC emission sources should be adjusted according to the variations in VOC emission characteristics and regional differences,so as to obtain the maximum environmental benefits.
基金supported by the Key Projects and Innovation Group of National Natural Science Foundation of China(81830065),the Innovation Groups of NSFC(81721001),and the Young Scientists Fund(82102279).
文摘Background Vascular hyporeactivity and leakage are key pathophysiologic features that produce multi-organ damage upon sepsis.We hypothesized that pericytes,a group of pluripotent cells that maintain vascular integrity and tension,are protective against sepsis via regulating vascular reactivity and permeability.Methods We conducted a series of in vivo experiments using wild-type(WT),platelet-derived growth factor receptor-β(PDGFR-β)-Cre+mT/mG transgenic mice and Tie2-Cre+Cx43^(flox/flox)mice to examine the relative contribution of pericytes in sepsis,either induced by cecal ligation and puncture(CLP)or lipopolysaccharide(LPS)challenge.In a separate set of experiments with Sprague-Dawley(SD)rats,pericytes were depleted using CP-673451,a selective PDGFR-βinhibitor,at a dosage of 40 mg/(kg·d)for 7 consecutive days.Cultured pericytes,vascular endothelial cells(VECs)and vascular smooth muscle cells(VSMCs)were used for mechanistic investigations.The effects of pericytes and pericyte-derived microvesicles(PCMVs)and candidate miRNAs on vascular reactivity and barrier function were also examined.Results CLP and LPS induced severe injury/loss of pericytes,vascular hyporeactivity and leakage(P<0.05).Transplantation with exogenous pericytes protected vascular reactivity and barrier function via microvessel colonization(P<0.05).Cx43 knockout in either pericytes or VECs reduced pericyte colonization in microvessels(P<0.05).Additionally,PCMVs transferred miR-145 and miR-132 to VSMCs and VECs,respectively,exerting a protective effect on vascular reactivity and barrier function after sepsis(P<0.05).miR-145 primarily improved the contractile response of VSMCs by activating the sphingosine kinase 2(Sphk2)/sphingosine-1-phosphate receptor(S1PR)1/phosphorylation of myosin light chain 20 pathway,whereas miR-132 effectively improved the barrier function of VECs by activating the Sphk2/S1PR2/zonula occludens-1 and vascular endothelial-cadherin pathways.Conclusions Pericytes are protective against sepsis through regulating vascular reactivity and barrier function.Possible mechanisms include both direct colonization of microvasculature and secretion of PCMVs.
基金supported by the National Science Centre of Poland within OPUS 16 Project,no.2018/31/B/ST8/01172。
文摘The sessile drop method was applied to the experimental investigation of the wetting and spreading behaviors of liquid Mg drops on pure Ni substrates.For comparison,the experiments were performed in two variants:(1)using the Capillary Purification(CP)procedure,which allows the non-contact heating and squeezing of a pure oxide-free Mg drop;(2)by classical Contact Heating(CH)procedure.The high-temperature tests were performed under isothermal conditions(CP:760℃for 30 s;CH:715℃for 300 s)using Ar+5 wt%H_(2) atmosphere.During the sessile drop tests,images of the Mg/Ni couples were recorded by CCD cameras(57 fps),which were then applied to calculate the contact angles of metal/substrate couples.Scanning and transmission electron microscopy analyses,both coupled with energy-dispersive X-ray spectroscopy,were used for detailed structural characterization of the solidified couples.It was found that an oxide-free Mg drop obtained by the CP procedure showed a wetting phenomenon on the Ni substrate(an average contact angleθ<90°in<1 s),followed by fast spreading and good wetting over the Ni substrate(θ_((CP))~20°in 5 s)to form a final contact angle ofθ_(f(CP))~18°.In contrast,a different wetting behavior was observed for the CH procedure,where the unavoidable primary oxide film on the Mg surface blocked the spreading of liquid Mg showing apparently non-wetting behavior after 300 s contact at the test temperature.However,in both cases,the deep craters formed in the Ni substrates under the Mg drops and significant change in the structure of initially pure Mg drops to Mg-Ni alloys suggest a strong dissolution of Ni in liquid Mg and apparent values of the final contact angles measured for the Mg/Ni system.
基金the Guiyang Research Academy of Eco-Environmental Science for partial support of this project。
文摘A survey was conducted of the volatile organic compounds(VOCs)released from sources of solvent use,industry activities and vehicle emissions in Guiyang,a capital city of China.Samples were collected by canisters and analyzed by GC-MS-FID.The species profiles of VOCs emitted from sources were obtained.Results showed that xylenes,ethylbenzene,acetone and dichloromethane were the characteristics species for painting,2-propanol and ethyl acetate for printing,α-pinene for solid wood furniture manufacturing,and 2-butanone for biscuit baking.These characteristics species could be as tracers for the sources respectively.In most of samples from the solvent use,the benzene/toluene(B/T)ratio was less than 0.3,indicating that the ratio could be as the indicator for tracing the solvent use related sources.The results also suggested that the toluene/xylene(T/X)ratio be as the indicator to distinguish the VOCs sources of painting(<2)from the printing(>2).Aromatics contributed the most to ozone formation potential(OFP)of most painting and non-paper printing sources,and oxygen-containing VOCs(OVOCs)were major species contributing to OFP of the sources from food production and paper printing.The OFP of the VOCs emissions from vehicle in tunnels and from other manufactures were dominated by both aromatics and alkenes.Theα-pinene could explain 56.94%and 32.54%of total OFP of the VOCs sources from filing cabinet and solid wood furniture manufacturing,which was rarely been involved in previous studies of VOCs source profiles,indicating that the species of concern for VOCs sources are still insufficient at present.
基金supported by the National Projects of the National Research Foundation(NRF)funded by Republic of Korea(#2022R1F1A1072739 and#2022R1A2C1004392)Prof.Nashrah is also grateful for financial supports by the YU Infra-Project in conjunction with BK21 FOUR National Program(#222A251009)by the Nano-Fab-NRF grant funded by Republic of Korea(#2009-0082580).
文摘The trade-off between efficiency and stability has limited the application of TiO_(2)as a catalyst due to its poor surface reactivity.Here,we present a modification of a TiO_(2)layer with highly stable Sub-5 nm Fe_(2)O_(3)nanoparticles(NP)by modulating its structure-surface reactivity relationship to attain efficiency-stability balance via a voltage-assisted oxidation approach.In situ simultaneous oxidation of the Ti substrate and Fe precursor using high-energy plasma driven by high voltage resulted in uniform distribution of Fe_(2)O_(3)NP embedded within porous TiO_(2)layer.Comprehensive surface characterizations with density functional theory demonstrated an improved electronic transition in TiO_(2)due to the presence of surface defects from reactive oxygen species and possible charge transfer from Ti to Fe;it also unexpectedly increased the active site in the TiO_(2)layer due to uncoordinated electrons in Sub-5 nm Fe_(2)O_(3)NP/TiO_(2)catalyst,thereby enhancing the adsorption of chemical functional groups on the catalyst.This unique embedded structure exhibited remarkable improvement in reducing 4-nitrophenol to 4-aminophenol,achieving approximately 99%efficiency in 20 min without stability decay after 20 consecutive cycles,outperforming previously reported TiO_(2)-based catalysts.This finding proposes a modified-electrochemical strategy enabling facile construction of TiO_(2)with nanoscale oxides extandable to other metal oxide systems.
文摘The importance of selective synthesis of high-value-added chemicals from renewable resources is paramount but remains a crucial challenge in organic synthesis and chemical reformation.Herein,we report the selective photosynthesis of C-C coupling products and carbonyl compounds from biomass-derived alcohols.The key to ensuring high end-to-end selectivity is the modulation of the reactivity of ketyl radical(*RCHOH)intermediates by employing different metal co-catalysts(Au,Pt,Pd,Ru)supported on Cd0.6Zn0.4S solid solution(CZS)photocatalysts.In particular,the C-C coupling product,hydrobenzion,and fully oxidized benzaldehyde were obtained from benzyl alcohol with high selectivity(>98%)over Au-CZS and Ru-CZS,respectively.Combined experimental and theoretical analyses demonstrated that the affinity of*RCHOH for the surface of metals governs their subsequent transformations,in which weak and strong radical adsorption on Au and Ru results in C-C coupling products and carbonyl compounds,respectively.
文摘Following publication of the original article,the authors observed that both Fig.5 and Fig.4 depict the same image.Figure 5 was inaccurately referenced and displayed.The correct Fig.5 is copied below:The original article has been updated.
基金the SINOPEC(124015)and the State Key Laboratory of Engines at Tianjin University(No.K2022-06).
文摘The aim of this study was to investigate the oxidation reactivity and behavior of exhaust particulate matter(PM)from diesel engines.PM samples from two diesel engines(1K,CY4102)with different emission levels were collected by a thermophoretic system and a quartz filter.The oxidation reactivity,oxidation behaviors,and physicochemical properties of the PM samples were analyzed using thermogravimetric analysis(TGA),high-resolution transmission electron microscopy(HRTEM),Fourier-transform infrared spectrometry(FTIR),and Raman spectroscopy.The results showed that there was a great difference in the oxidation reactivity of soot particles emitted by the two different diesel engines.A qualitative analysis of the factors influencing oxidation reactivity showed that the nanostructure,degree of graphitization,and relative concentration of aliphatic C—H functional groups were the most important factors,whereas no significant correlation was found between the primary particle size and activation energy of the diesel soot.Based on the oxidation behavior analysis,the diesel soot particles exhibited both internal and surface oxidation modes during the oxidation process.Surface oxidation was dominant during the initial stage,and as oxidation progressed,the mode gradually changed to internal oxidation.Internal oxidation mode of soot particles from the 1K engine was significantly higher than that of CY4102.
文摘The reactivity and stability of seventeen (17) imidazo [1,2-a]pyridine N-acylhydrazone derivatives were investigated using density functional theory at the B3LYP/6-31+ G (d, p) level. Analysis of the molecular electrostatic potential (MEP) and determination of the dual descriptor revealed that in most cases, the nitrogen atoms of the 6-πelectron conjugation, the oxygen, and the sulfur atom are nucleophilic site. Chemical reactivity of the compounds was assessed through analysis of frontier molecular orbitals (HOMO and LUMO), energy gap (Δℰ), chemical hardness (η), and the softness (S). Consequently, the compound 9e exhibited the lowest reactivity, least electron donating, and the highest stability. This comprehensive study offers valuable insights into the chemical behavior of these derivatives, crucial for further exploration and potential applications.
文摘Several works have been based on the study of thermal variations in biomass to derive more valuable products such as fuels capable of replacing oil in the event of a crisis or activated carbon used as an adsorbent material, widely used in industry for the elimination of unwanted materials, both in liquid and gaseous environments. A study of thermal parameters such as: heating speed, retention time, drying temperature, carbonization temperature, particle size, was carried out with the aim of determining the characteristic factors of the carbonization of Polyethylene terephthalate (PET), sawdust (SC) and sawdust/polyethylene terephthalate (CPS) mixture. The results of the immediate analysis revealed a very low level of ash in PET (0.013%) compared to the level of ash in sawdust (2.9%), as well as a high level of fixed carbon (82.960%), which suggests the presence of mineral oxides and a significant carbon matrix unlike PET, which indicates a very significant organic matrix (essentially made up of organic matter) with the absence of mineral oxides. The study of thermal parameters showed the water loss from Sawdust (SC) and the Sawdust/Polyethylene terephthalate (CPS) mixture, an increase with temperature, unlike that of PET whose variation is essentially zero. Without heat treatment, sawdust alone contains approximately 7% water. The optimal drying temperature for this study is 110˚C for a stay of 24 hours. It appears that the largest mass losses for the PET samples are between 87.19% and 96.05%, followed by that of the mixture, between 47.33% and 64.37%. And the lowest are observed, those of sawdust (from 24.02% to 62.6%). However, here we can say that the influence of the mass is not great, given the slight difference between the losses by temperature. The results of the study of the influence of grain size showed that the differences are insignificant, even if we vary the diameter of the grains from simple to triple. To better minimize physical constraints such as the intragranular diffusibility of the volatile matter and the homogeneity of the temperature in the grains, 75 μm particles are found to be optimal for our study. It can be noted when studying the heating rate that the mass loss at the end of the reaction is approximately the same depending on each precursor material. However, it has been demonstrated that the heating rate strongly influences the nature of the reaction products both for volatile materials and for the solid residue as well as on the kinetic parameters of the chemical reaction. Furthermore, the variation in apparent density shows a decrease as a function of the increase in the residence time of the materials in the reactor. As the carbonization time increases, the apparent density decreases. We note, for the lignocellulosic material, that the apparent density stabilizes after 60 minutes.
基金Project (50864001) supported by the National Natural Science Foundation of China
文摘The electronic property of pyrite supercell containing As,Se,Te,Co or Ni hetero atoms were calculated using density functional theory（DFT）,and the reactivities of pyrite with oxygen and xanthate were discussed by frontier orbital methods.The cell volume expands due to the presence of impurity.Co and Ni mainly affect the bands near Fermi levels,while As mainly affects the shallow and deep valence bands,and Se and Te mainly affect the deep valence bands.Electronic density analysis suggests that there exists a strong covalent interaction between hetero atom and its surrounding atoms.By frontier orbital calculation,it is suggested that As,Co and Ni have greater influence on the HOMO and LUMO of pyrite than Se and Te.In addition,pyrite containing As,Co or Ni is easier to oxidize by oxygen than pyrite containing Se or Te,and pyrite containing Co or Ni has greater interaction with collector.These are in agreement with the observed pyrite practice.
基金Project(51374253)supported by the National Natural Science Foundation of China
文摘Effect of sulfur impurity on coke reactivity was investigated by simulating petroleum coke with low-impurity pitch coke and impurities doping. And its mechanism was discussed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The results show that sulfur has strong catalysis on both air and CO2 reactivity of coke in the case of no other impurity interference. Its catalysis is probably realized by triggering organic sulfur→H2S→SO2→COS and elemental sulfur (Sx)→SO2 and organic sulfur→H2S→COS→Sx→C2S→COS reaction systems during coke?O2 and coke?CO2 reactions, respectively, which are partly circular with functions of increasing carbon consumption and enlarging coke specific surface area.
基金supported by the National Natural Science Foundation of China (21573232, 21576251, 21676269)National Key Projects for Funda-mental Research and Development of China (2016YFA0202801)Department of Science and Technology of Liaoning province under contract of 2015020086–101~~
文摘The formations and transformations of the chemical bonds of reactants and intermediates on cata- lyst surfaces occur in conjunction with the evolution of heat during catalytic reactions. Measure- ment of this evolved heat is helpful in terms of understanding the nature of the interactions be- tween the catalyst and the adsorbed species, and provides insights into the reactivity of the catalyst. Although various techniques have previously been applied to assessments of evolved heat, direct measurements using a Tian-Calvet microcalorimeter are currently the most reliable method for this purpose. In this review, we summarize the relationship between the adsorption/reaction energetics determined by microcalorimetry and the reactivities of supported catalysts, and examine the im- portant role of microcalorimetry in understanding catalytic performance from the energetic point of view.
基金Beijing Higher Education Young Elite Teacher Project(Grant No.YETP0064)from Beijing Municipal Education Commission
文摘Various platelet function tests are currently used to identify responsiveness to antiplatelet therapy. 176 ACS patients were enrolled and Linear regression and Kappa consistency analysis showed there was a significant but moderate correlation between platelet inhibition rate and a significant but fair agreement between high clopidogrel on-treatment platelet reactivity tested by light transmission aggregometry and thrombelastography.
基金the Science Fund for Distinguished Young Scholars from the Fourth Affi liated Hospital of Harbin Medical University(no.HYDSYJQ201504)The funders had no role in the study design,data collection and analysis,decision to publish,or preparation of the manuscriptThe clinical trial is registered as ChiCTR-IOR-17013665。
文摘Objectives:We sought to determine whether high posttreatment platelet reactivity(HPPR)to a 600 mg loading dose of clopidogrel affects outcomes in Chinese patients with acute coronary syndrome(ACS)following percutaneous coronary intervention(PCI)and to investigate whether there is a relationship between the number of platelet reactivity units(PRUs)and the characteristics of the patients.Background:Although impaired platelet response to clopidogrel is a strong predictor of unfavorable outcome after PCI,the impact of HPPR to a 600 mg loading dose of clopidogrel in Chinese patients with ACS undergoing PCI is still unknown.Methods:We performed observational research on 134 unselected patients with ACS undergoing urgent or planned PCI with a 600 mg loading dose of clopidogrel.Platelet activation was expressed as the PRU value measured by the VerifyNow assay.Results:Among the 134 patients(mean age 60.62 years[standard deviation 9.13 years],60.4%male),there were 46 patients with HPPR(34.3%)and 88 patients without HPPR(65.7%).At a mean follow-up of 6 months(standard deviation 1 month),the rates of cardiac death,unstable angina,and rehospitalization for target lesion revascularization were higher in the HPPR group(19.6%vs.6.8%,P=0.029).Multivariate analysis identifi ed hemoglobin level and sex as independent predictors of the PRU value(y=456.355−1.736 x 1−31.880 x 2,P<0.05).On receiver operating characteristic curve analysis,PRU values could signifi cantly discriminate between patients with and patients without cardiac death,unstable angina,and rehospitalization for target lesion revascularization(area under the curve 0.758,95%confi dence interval 0.62–0.85,P=0.001,P<0.05).Conclusion:In patients with ACS,HPPR to a 600 mg loading dose of clopidogrel is associated with worse outcomes after PCI.There is some relationship between the PRU value and the hemoglobin level and sex.PRU values can predict the prognosis.
文摘The paper describes the instrumentation for studying temperature and void reactivity effects that were developed at VR-I zero power reactor. Further are described its operational parameters, fields and ways of its utilization as well as issues connected to its implementation into the reactor core.
文摘Antiplatelet therapy with aspirin or clopidogrel or both is the standard care for patients with proven coronary or peripheral arterial disease,especially those undergoing endovascular revascularization procedures. However,despite the administration of the antiplatelet regiments,some patients still experience recurrent cardiovascular ischemic events. So far,it is well documented by several studies that in vitro response of platelets may be extremely variable. Poor antiplatelet effect of clopidogrel or high on-treatment platelet reactivity(HTPR) is under investigation by numerous recent studies. This review article focuses on methods used for the ex vivo evaluation of HTPR,as well as on the possible underlying mechanisms and the clinical consequences of this entity. Alternative therapeutic options and future directions are also addressed.
